Green Drakes continue

The hatch is still going. On Tuesday last Tom and I tried a stretch of the river just outside of town.
Not many green drakes were visible in the air but that did not stop the fish from taking the dry.
Tom was happily catching fish on a green drake pattern, so I switched up a bit to
see what the fish would take. I tired a large (size8) yellow simulator pattern, but it did not generate much interest. I then switched to a size 12 yellow parachute stonefly pattern.
It was well received by the fish.

Lately I have noticed that late in the evening the fish sem to be switching to a caddis pattern, so I stitched over to a size 12 Elk Hair Caddis. It worked just fine, but Tom continued to catch fish on the green drake pattern which suggests the fish were not being particularly selective that night..
.
Just the other day I was fishing with Dan and his buddy Mark. They had been out the evening before and done quite well on large yellow stone fly patterns. We returned to the same water the next evening, but we arrived a bit earlier in the day.
Mark heading upstream to the water he did very well in the night before, while Dan and I hit a nice pool just down around the corner.
Dan started fishing the water with the large stone he was using the might before and covered the water well, but did not raise a fish.
When Dan gracefully yielded the water to me, I covered it with a Green Drake pattern since I knew that the drakes were coming off starting about 3:00 pm while the stone are out later in the day.
It worked, and I rose several fish in the next few casts.
The point is that just because a fly worked well one night does not mean that it will perform equally well the next day. Two main factors come into play to effect this.
One: On the Upper Sac the last few hours of light are the magic time, often any well presented fly will work, the fish are in a feeding mode and will take most anything.
Two: At different times of the day different bugs are available to the fish and they will often key on the most numerous bugs at a specific time.

I have been talking about yellow stonefly patterns.

It is much more common to fish this river with a golden stone fly pattern in some flavor of orange. But this year I have noticed that the stones that are coming off right now have a very yellow body. I think that they are still a golden stone, but why the usual amount of yellow in them I do not know. We will see if the color changes as we get into the meat of the hatch which should happen in the next two weeks. .